From fe929c171966c6102452f3612c613a245a5e8bb7 Mon Sep 17 00:00:00 2001 From: Ryuta Kamizono Date: Wed, 8 Aug 2018 06:35:13 +0900 Subject: Don't update counter cache unless the record is actually saved This is a 4th attempt to make counter cache transactional completely. Past attempts: #9236, #14849, #23357. All existing counter cache issues (increment/decrement twice, lost increment) are caused due to updating counter cache on the outside of the record saving transaction by assigning belongs_to record, even though assigning that doesn't cause the record saving. We have the `@_after_replace_counter_called` guard condition to mitigate double increment/decrement issues, but we can't completely prevent that inconsistency as long as updating counter cache on the outside of the transaction, since saving the record is not always happened after that. We already have handling counter cache after create/update/destroy, https://github.com/rails/rails/blob/1b90f614b1b3d06b7f02a8b9ea6cd84f15d58643/activerecord/lib/active_record/counter_cache.rb#L162-L189 https://github.com/rails/rails/blob/1b90f614b1b3d06b7f02a8b9ea6cd84f15d58643/activerecord/lib/active_record/associations/builder/belongs_to.rb#L33-L59 so just removing assigning logic on the belongs_to association makes counter cache transactional completely. Closes #14849. Closes #23357. Closes #31493. Closes #31494. Closes #32372. Closes #33113. Closes #33117 Closes #33129. Closes #33458. --- .../active_record/associations/belongs_to_association.rb | 16 ---------------- .../associations/belongs_to_polymorphic_association.rb | 4 ---- .../lib/active_record/associations/builder/belongs_to.rb | 4 +--- 3 files changed, 1 insertion(+), 23 deletions(-) (limited to 'activerecord/lib/active_record') diff --git a/activerecord/lib/active_record/associations/belongs_to_association.rb b/activerecord/lib/active_record/associations/belongs_to_association.rb index 3d4ad1dd5b..544aec5e8b 100644 --- a/activerecord/lib/active_record/associations/belongs_to_association.rb +++ b/activerecord/lib/active_record/associations/belongs_to_association.rb @@ -50,11 +50,8 @@ module ActiveRecord def replace(record) if record raise_on_type_mismatch!(record) - update_counters_on_replace(record) set_inverse_instance(record) @updated = true - else - decrement_counters end replace_keys(record) @@ -80,19 +77,6 @@ module ActiveRecord reflection.counter_cache_column && owner.persisted? end - def update_counters_on_replace(record) - if require_counter_update? && different_target?(record) - owner.instance_variable_set :@_after_replace_counter_called, true - record.increment!(reflection.counter_cache_column, touch: reflection.options[:touch]) - decrement_counters - end - end - - # Checks whether record is different to the current target, without loading it - def different_target?(record) - record._read_attribute(primary_key(record)) != owner._read_attribute(reflection.foreign_key) - end - def replace_keys(record) owner[reflection.foreign_key] = record ? record._read_attribute(primary_key(record)) : nil end diff --git a/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb b/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb index 3fd2fb5f67..9ae452e7a1 100644 --- a/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb +++ b/activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb @@ -19,10 +19,6 @@ module ActiveRecord owner[reflection.foreign_type] = record ? record.class.polymorphic_name : nil end - def different_target?(record) - super || record.class != klass - end - def inverse_reflection_for(record) reflection.polymorphic_inverse_of(record.class) end diff --git a/activerecord/lib/active_record/associations/builder/belongs_to.rb b/activerecord/lib/active_record/associations/builder/belongs_to.rb index 0166ed98ca..da4cc343eb 100644 --- a/activerecord/lib/active_record/associations/builder/belongs_to.rb +++ b/activerecord/lib/active_record/associations/builder/belongs_to.rb @@ -34,9 +34,7 @@ module ActiveRecord::Associations::Builder # :nodoc: foreign_key = reflection.foreign_key cache_column = reflection.counter_cache_column - if @_after_replace_counter_called ||= false - @_after_replace_counter_called = false - elsif association(reflection.name).target_changed? + if association(reflection.name).target_changed? if reflection.polymorphic? model = attribute_in_database(reflection.foreign_type).try(:constantize) model_was = attribute_before_last_save(reflection.foreign_type).try(:constantize) -- cgit v1.2.3